The Human Tissues and Organs for Research (HTOR) program of the National Disease Research Interchange is dedicated solely to accessing and providing human tissues for research purposes. These tissues and organs are essential for the great majority of research projects served by HTOR and the program is clearly relevant to advancing human health. HTOR's long-term objective is to increase the quantity, diversity, and quality of human research tissues available for research. The collection, preparation, and preservation of the tissues must be performed according to researcher-specified protocols for the materials to be useful to scientists. The acquisition of these materials requires an extensive national network of acquisition sites such as hospital pathology and surgical services, eye and tissue banks, and Organ Procurement Organizations. HTOR's unique systems ensure that tissues procured for customized protocols are delivered in a timely manner to the appropriate research destinations. The quantity, quality and diversity of tissues shipped to investigators is a function of three critical variables: the number and types of Sources working with HTOR, the internal systems of HTOR, and the number and types of research requests that HTOR receives from Researchers. The Specific Aims of the proposed funding period focus on strengthening these three arms of the HTOR program (Sources, Information Systems, and Researchers). HTOR will work to increase the capabilities of existing sources and add new sources to increase tissue quantity and diversity (Aim 1/Sources); upgrade HTOR's Internal Systems (computer hardware, software, and data management) to improve data capture and analysis, and upgrade the HTOR Web Site to increase Source and Researcher access to HTOR resources (Aim 2/Systems); and work closely with the research community to fulfill existing and emerging needs for human research tissue (Aim 3/Researchers). In addition, HTOR will continue a specialized program for procuring and distributing HIV positive tissues (Aim 4), a goal that is also consistent with HTOR's long-term objective.